The Evolution of Beauty

It’s been nearly 160 years since the publication of Charles Darwin’s the origin of species with its dazzling description of a model for the evolution of life inspired by those lovely whimsical finches. In that time, Evolutionary Science has advanced a long way, but according to Yale Ornithologist Richard Prum, something also has been lost: a scientific accounting, not just of the functional advantages that drive evolution, but of the aesthetics of animal sexuality that inspire individual choice.

He develops this theory in the new book The Evolution of Beauty: How Darwin’s Forgotten Theory of Mate Choice Shapes the Animal World – and Us which he will discuss at an upcoming Town Hall event on Monday, June 11 at the PATH Auditorium in downtown Seattle. But in the meantime we arranged a conversation between him and Grace Hamilton. Grace is a PhD candidate in the Department of Biochemistry at the University of Washington and a participant in this year’s UW ScienceEngage program for public science communication. They spoke about the evolution of beauty, the terrifying arms race of duck genitalia and the queering of Homo Sapiens.

Grace Hamilton: I wanted to tell you first how much I enjoyed your book The Evolution of Beauty.

Richard Prum: I’m glad! That’s why you write it, to hopefully get some readers on the other end.

GH: Yeah, I’m not an ornithologist or an evolutionary biologist by training, but I really enjoyed the intellectual passion you bring to the task of resurrecting Darwin’s long neglected theory of mate choice, your dissection of the cultural biases that drove it out of the scientific mainstream in the first place, and the hypotheses about human evolution that this theory of aesthetic evolution provoked. Could you briefly define aesthetic evolution for listeners who haven’t yet had the pleasure of reading your book?

RP: Aesthetic evolution is a process that involves a sensory perception, a cognitive evaluation, and some kind of social or sexual choice. And when these three things come together with some kind of heritable substrate or genetic or cultural substrate, then the result is a distinct kind of evolution that I have called aesthetic evolution. And it’s distinct because the features that evolve this way function in the perception of animals, not in the physical world. So we can compare, for example, the roots of a plant to the flower of the plant. The roots we could describe entirely in terms of their physical functions: holding the plant into the soil, absorbing water and nutrients of some kinds and also interacting with bacteria or fungi in the soil, these kinds of things. But the flower functions in the brain—if you will—of the bee or the hummingbird, the pollinator. And in that way, it functions in a distinct fashion where perception and essentially the taste of the animals matters.

GH: But this isn’t how the field of Evolutionary Biology, how they tend to view traits. Usually the argument is that these traits are not just for the perceptual benefit of others, but that they must convey some sort of information about reproductive value. So what led you down this very different mode of viewing evolution?

RP: Yeah, quite right. The majority of my colleagues think that the pleasure of animals or the subjective experiences of animals, if you will—what it is like to be a bird listening to a song or a bee looking at a flower—most of my colleagues think that these experiences need to be explained away, that is as some kind of utility. And this is a worldview that requires that requires that adaptation by natural selection is a strong force that kind of dominates all the events in evolutionary history. However, somehow or other, the way I have connected my own personal history as a birdwatcher and as a national historian to my scientific research, I’ve just been attracted to another idea, a different theory, and it’s one that actually is historically the original one proposed by Darwin in 1871. And that is the idea that beauty can evolve because of the pleasure it produces, because of the fact that animals like it, right? And that alone can drive the evolution of ornament, sexual ornament in nature in many different ways that are unpredicted by adaptation.

GH: You study one of the most classically beautiful areas of biology, the birds, and what made you think that these ideas initially based on the observation of birds and their mating behavior, could be fruitfully applied to human evolution as you do so excitingly, in The Evolution of Beauty?

RP: Yeah. Well, a lot of my colleagues ask me “Rick, why would you create this mess for yourself? Why would you get involved with talking about people?” and there’s a lot of reasons. One: people are important! How we think about our own sexuality, our own sexual selves, our own beauty has really been influenced greatly by the same kind of science that I have been battling essentially in ornithology. That is the idea from evolutionary psychology and sociobiology, areas of evolutionary biology that have worked on human evolution, have been trying to support the idea that human beauty, whether it’s asymmetry or waist-to-hip ratio or various kinds of aspects of human beauty are all indicators of genetic or quality or condition. Right? And, and I think much of this work is notably bad science, and so that’s one reason to counter it, but it also has, I think, come to influence how people think about themselves. How humans think about their own sexual self.

So I think children or teenagers today grow up looking in the mirror with more challenges than teenagers had in the past in the sense that they look at every asymmetry or every difference from maybe canonical descriptions of beauty and imagine that that indicates actually objective qualities of themselves. And that idea is just deeply flawed scientifically and deeply damaging culturally. And so one of the reasons why to take on the evolution of human sexuality was to try to address that and propose a different path to understanding how we got here, how we got to be this way.

GH: In your book I found it very poignant your discussion of this bad science that often occurs in evolutionary psychology. How there are attempts to “quantify” even female beauty—and usually female beauty—in terms of things like waist-to-hip ratio or facial asymmetry.

RP: One of the oddities of the field is it takes a lot of intellectual shortcuts, but one that’s really prominent is to state that sperm are cheap and eggs are rare and expensive, relatively, and therefore males should be profligate and females should be sexually coy. And this has typically been played out as a sort of rich explanation of human reproductive biology. And I try to document in the book how failed that really is in many ways.

GH: And you cite a sort of intellectual antipathy towards the evolutionary power as female sexual autonomy as something that goes all the way back to Darwin and something that may have predisposed many evolutionary biologists to be hostile to aesthetic evolution.

RP: You know, a number of reviews and some of my colleagues have asked me: “why get into the political history of evolutionary biology and some of these topics?” And I think it’s responsible as a scientist to understand the implications of your statements, so I’ve gotten into these issues because I think that the culture has influenced the science—and not in a good way.

GH: You’ve done fascinating, and in some quarters notorious, research into the torrid sex lives of ducks.

RP: Yeah. I’ve come to realize that duck sex is like a gas; it expands to fill whatever volume you put it in. Keeping it hemmed in a little bit. Yes, we have been working duck sex with my former Postdoc, Patricia Brennan, now a professor at Mount Holyoke College in Massachusetts, and her work has really been revolutionary in understanding an area of Evolutionary Biology called sexual conflict. It turns out it is quite related to the evolution of beauty and it’s really about what happens when freedom of mate choice is infringed or violated by sexual coercion or sexual violence. So the rather violent and troubling sex lives of the ducks turn out to be really instrumental in understanding sexual conflict in a new way. And that’s a big focus of the book.

GH: I was struck by your discussion of this research in The Evolution of Beauty. You assert that the revelation of an aesthetic mechanism for the evolution of female sexual autonomy in waterfowl is a profound feminist scientific discovery. What does it mean for a scientific finding to be feminist?

RP: Well, since the 70’s and on, there has been a fascinating literature in feminist science, feminist biology. But much of it is a cultural critique of science itself, and that’s not what I’m referring to. I’m not talking about science that starts with some kind of political conclusions or assumptions and then elaborate theories. I’m talking about finding that aspects of the political and cultural debate of feminism—and by contrast, patriarchy—are actually evolved in other species than human beings. In the case of duck sex, the discovery is that freedom of choice matters to animals, right? There is something it is like to have freedom of choice, and as a result when freedom of choice is violated by coercion or sexual violence, there turned out to be evolutionary consequences of that.

And the way in which they work is deeply fascinating and I think actually informative to both human evolutionary biology and contemporary culture. So I think of this as a feminist discovery in the sense that we’re finding out that the concerns of human culture and of human wellbeing and thriving are not unique to us. Sexual autonomy is not a concept discovered by suffragettes and feminist in the 19th and 20th century only. It is an evolved feature of the social sexual lives of other kinds of animals. And that opens up a whole new kind of conversation between evolutionary biology, feminism, and gender theory that I’m very excited about.

GH: It’s fascinating stuff. But because of this research funded by the National Science Foundation, studying sexual autonomy and a sort of terrifying genital arms race between male and female ducks, you were briefly the right-wing poster child for profligate government spending. What was that like? That sounds like every scientist’s nightmare.

RP: Well, it was a bit horrifying. So what happened was during one particular phase of debate about government spending during the Obama administration, our grant to study the evolution of the evolution duck sex, the co-evolution of sexual conflict in ducks, was found by a right wing think tank and then soon became the subject of Fox News and other attacks. You know, it was sobering. But one of the things that we were confident of is that duck sex is fascinating, right? The fact of the matter is that the reason why they picked—in one case, $30 billion of government waste and they’re picking on our $350,000 grant—the reason why it’s so fascinating is that duck sex is fascinating! And we knew that if we had, if you will, a fair fight or a level playing field that people would find it fascinating and worthwhile

GH: And it’s not just the sex lives of ducks though, that you talk about in The Evolution of Beauty. You have a whole chapter called “The Queering of Homo Sapiens” in which you— and I’ve heard several theories about the evolution of homosexuality in humans, the idea that it’s kin selection, that this will somehow benefit the nieces and nephews of people with exclusively same-sex attractions—but you posit a new theory that I hadn’t heard before: that males with traits associated with same-sex preferences were actually preferred as mates by females. I was wondering if anyone had pointed out that this theory is an inversion of a classic lament that all the good ones are gay. You’re saying that rather than all the good ones are gay, all the gay ones are good—as in desirable.

RP: Well, you know, starting with a study with a human sexuality is complicated because of course there’s a lot going on! You know, there’s male choice, female choice, male/male competition, female competition, sexual conflict, and culture all piled on top. And so I originally imagined one chapter on human sexuality, but it turned into four because doing it responsibly took so much more time. But you’re right, there is a chapter on the evolution of same-sex preferences and attractions and that I, it as you stated, propose a new theory. And basically what I’m proposing is that same-sex behavior, both between women and men, evolved because it furthered female sexual autonomy during our human evolution. That is, female/female sexual interactions would foster alliances that were appropriately defensive against male sexual and social control—essentially a male hierarchy—and that male/male sexual interactions would also further a social environment that would be less focused on the control of female sexuality and allow females with more social opportunities to further their own autonomous interests.

And so what this means is interesting in two ways. One: it is congruent with the more conservative hypothesis that may be represented by Andrew Sullivan, who wrote a book called Virtually Normal. Which was basically that the gay couple next door are just like everybody else except for who’s in their bed, right? And this is the sort of normalizing view. And it’s true in that sense that I think that this is a deep part of evolutionary history, of the changing of the evolution of a pro-social human species.

However, this hypothesis is also congruent with the more radically queer theorists within the discipline who see same-sex behavior as inherently disruptive. And the reason why I use the term “queering” of Homo Sapiens is to say that same-sex attraction I think evolved specifically because it functions to undermine male social and sexual hierarchy. That is, it evolved because of this feature, which means that there is something inherently queer about it. “Queering” in the sense of undermining the normal, undermining the control, undermining in this case male social control. So I think there’s something for everybody in there. This is a way of opening up the topic that begins with the aesthetic. Previous theories have tried to explain same-sex behavior through its indirect or correlated features, right? But I’ve been saying that at the center of this biology is subjective experience.

What is it that animals want? What do they prefer? And in this case, when it comes to the diversity of human sexual preferences and desires, we can see that we can’t just explain it away as “oh, gay folks are helping raise their nieces and nephews and therefore that’s how the genes are propagated,” right? These are end-arounds, these are dodges, if you will. The real issue is the evolution of desire itself. And that’s something that other previous theories have not gotten to. And so I’m trying to propose that, and by taking the aesthetic view that means that that becomes our, our main question: how does desire itself, how does the object of desire, evolve? And that’s, I think, why it’s been a successful idea.

Richard Prum is the author of The Evolution of Beauty: How Darwin’s Forgotten Theory of Mate Choice Shapes the Animal World – and Us out now from Doubleday books. He spoke with Grace Hamilton, PhD Candidate in Biochemistry at the University of Washington. He will be speaking about the book on Monday, June 11 at 7:30pm at the PATH Auditorium.